You’re in the middle of an easy 10-miler on a trail just outside of town. While up on little-used ridge top trail, you twist your ankle and snap your fibula. You get up and try to hobble down the trail, but the terrain is too technical for you to make worthwhile progress. Seeing as how you were only going for a short training run on local trails you left your cellphone and Spot Satellite Messenger (iRunFar discussion of Spot) at home, so you can’t contact a buddy for help. You’re also too far from town for any to hear you call for help and there’s little hope of another person being within earshot. What are you to do? Improvise an emergency signal mirror.

A proper emergency signal mirror can easily be seen for 10+ miles (there are reports of sightings from up to 100 miles) and can still be effective under overcast skies and even with bright moonlight. The principle behind an signal mirror is that a flash of light produced from the mirror will catch the eye of individuals, including search and rescue personnel. Signal mirrors are standard items for emergency kits, as well as mandatory gear for races such as the Marathon des Sables.

When you need but don’t have an emergency signal mirror, one can be improvised. The face of a Garmin Forerunner 205 or 305 (available from Backcountry.com), the mirrored back of iPod, other highly reflective surfaces, or even broken glass will do. While true emergency signal mirrors generally have a built in sighting mechanism, aiming an improvised signal mirror takes a bit more skill. There are two techniques for aiming an improvised signal mirror (1) the hand method (picture at upper left) and (2) stick method (left). Rather than attempt to reinvent the wheel…. er, signal mirror, we’ll direct you to survival experts who ably explain the finer points of improvised signal mirror use:

SurvivalIQ‘s Means for Signaling – Discusses a wider range of signaling techniques, including fire and smoke, as well as alternate exemplary images of both the hand and stick signal mirror aiming techniques.

Please let other iRunFar readers know if you have or know of anyone how has made effective use of an emergency signal mirror – improvised or not. Please also share any insight or alternate resources on emergency signaling that you know.

Cool. Last year I did a run in Utah and took along a small makeup mirror to signal the kids when I reached the top of a mountain. It was surprisingly effective over several miles (they signaled back with one, too). It took a while, but once we got the first hit it was easy to repeatedly 'flash' the target. I also tried using the back of a cd, and aiming through the center hole, but that didn't get any results at all.This pic shows where I was, the kids were down in the town below.http://farm2.static.flickr.com/1353/687901744_aacb35e4e9.jpgI wish I had known about that hand aiming method. Handy!Chris

> Please let other iRunFar readers know if you have or know of anyone how has made effective use of an emergency signal mirror – improvised or not

I've used signal mirrors a lot in practice (see my "website" for videos), and I've collected dozens of news stories of rescues with both improvised and manufactured mirrors. Here's a thread with news stories of signal mirror rescues from 2005 on – the most recent in Alaska, last Tuesday: http://forums.equipped.org/ubbthreads.php?ubb=sho…

> Please also share any insight or alternate resources on emergency signaling that you know.

There are lots of low tech, nearly zero cash outlay things you should do, like: (1) letting a trusted party know exactly what your route and schedule is, and when they should call search & rescue if you don't get back in time. A high-tech version of this (which I have not tried) is: http://www.trailnote.com/about.cfm
(2) Don't travel alone.

Getting back to the signal mirror – there are several radically different good ways of aiming them[1]. The V-finger method is pretty much the last resort. Here are the others:

(1) Retroreflective aimer (figure 2, method 4, in [1])

Here's where being prepared will really pay off. The 0.7 oz, $10 "SOL Rescue Flash" 2"x3" polycarbonate mirror sold at REI ( http://www.rei.com/product/813509/sol-rescue-flas… ), has this type of aimer, as have most US military signal mirrors since 1946. If you want a good signal mirror with minimum weight, this is the way to go.

The mirrors above have white aiming dots. If saving cash is more important to you than weight, you can put your own red retroreflective aimer on most any glass mirror, as shown here: http://www.youtube.com/watch?v=lTy-o5Ci4-k

(2) Foresight aimer (mimicing figure 2, method 2, in [1])

The "Vee-finger" aiming method is a form of this, but the problem is that the reflected mirror beam is much narrower at long range than it appears at close range. The beam is roughly the diameter the full moon, or of Lincoln's head on a US penny held at arm's length. Here's a photo showing that: http://www.flickr.com/photos/signalmirror/8422523…

Because the beam is so narrow, you want to line up the line from your eye to the target with the beam emitted by a very small point on the mirror. The trick to locating that point is to remove a small bit of the silver on the back of the mirror – no more than 1/4" diameter), look through that hole on the target, and capture the shadow cast by the hole in the mirror on a finger, then flick the shadow over your target. I discuss how to apply this method to a CD in detail in the text below this video showing my signal from 11 miles away: http://www.youtube.com/watch?v=xAvw2qLT4dU

(3) Rearsight aimer (figure 2, method 3, in [1])

This method requires a double-sided reflector, like the old Boy Scout metal mirrors with a hole in the center (that still come up on Ebay). The USAF survival manual does a great job illustrating this, so I'll just refer to that:http://www.flickr.com/photos/signalmirror/8419515…